Leslie Morphy, chief executive of the homelessness charity Crisis, said: ‘With homelessness on the rise and millions of people languishing on housing waiting lists, we must do more to increase the supply of affordable homes. This is not just a numbers game, but about creating mixed, vibrant communities and avoiding ghettoisation of rich and poor.’

Pete Robbins, Lambeth council cabinet member for housing and regeneration, says: ‘We are serious about delivering a high level of affordable housing in every new development that comes forward in Lambeth. But this is much harder now because of the viability tests that give developers a chance to avoid our affordable housing targets. We continue to work hard to maximise affordable housing levels, but the bottom line is that our hands are increasingly tied.’

Affordable housing targets are set by councils according to local supply and demand, alongside the costs of housing and wages.

The requirements are not legally binding, and if a developer can demonstrate that the target makes their particular development uneconomic, then the requirement can be reduced or even dropped.

Subscribe to the AJ

The Architects’ Journal is the UK’s best-selling weekly architecture magazine and is the voice of architecture in Britain

About the Architects' Journal

The Architects' Journal is the voice of architecture in Britain. We sit at the heart of the debate about British architecture and British cities, and form opinions across the whole construction industry on design-related matters